EFFECT OF INCREASING VERTICAL CENTRE OF MASS DISPLACEMENT ON THE BIOMECHANICAL STIMULUS OF TRADITIONAL RESISTANCE TRAINING EXERCISES

This study investigated the effect of systematically increasing vertical COM displacement on the biomechanical stimulus of a traditional resistance training exercise. Fourteen male rugby union athletes performed maximum velocity repetitions of the deadlift to four different final vertical positions with external loads of 20, 40 and 60% 1RM. Significant increases in force, velocity and power were obtained with lifting techniques that resulted in greater vertical COM displacement, although significant interaction effects revealed that improvements were attenuated with heavier loads. These results have applications to strength and conditioning practice, whereby the traditional resistance training exercise stimulus can be augmented without imposing the overly large eccentric musculoskeletal loads characteristic of landing from maximal weighted vertical jumps

EFFECT OF LOAD POSITIONING ON THE KINEMATICS AND KINETICS OF WEIGHTED JUMPS

The present study sought to examine the effect of altering the position of external loads on the kinematics and kinetics of weighted vertical jumps in 29 resistance trained rugby union athletes. Vertical jumps were performed with loads of 20, 40 and 60% squat 1RM with the load positioned: 1) on the posterior aspect of the shoulder using a traditional barbell (TBJ); and 2) at arms’ length using a hexagonal barbell (HBJ). Weighted jumps performed with the load held at arms’ length resulted in significantly greater values for jump height, peak force, peak power, and peak rate of force development (

Theodicy and End-of-Life Care

Acknowledgments The section on Islamic perspective is contributed by information provided by Imranali Panjwani, Tutor in Theology & Religious Studies, King's College London.Peer reviewedPublisher PD

Including supramaximal verification reduced uncertainty in VO2peak response rate.

Many reports describe using a supramaximal verification phase - exercising at a power output higher than the highest power output recorded during an incremental cardiopulmonary test - to validate VO2max. The impact of verification phases on estimating the proportion of individuals who increased VO2peak in response to high-intensity interval training (HIIT) remains an underexplored area in the individual response literature. This analysis investigated the influence of same-day and separate-day verification phases during repeated measurements (incremental tests – INCR1 and INCR2; incremental tests + supramaximal verification phases – INCR1+ and INCR2+) of VO2peak on typical error (TE) and the proportion of individuals classified as responders (i.e. the response rate) following four weeks of HIIT (n=25) or a no-exercise control period (n=9). Incorporation of supramaximal verification consistently reduced the standard deviation of individual response, typical error, and confidence interval widths. However, variances were statistically similar across all groups (p>0.05). Response rates increased when incorporating either one (INCR1 to INCR1+; 24% to 48%, p=0.07) or two (INCR2 to INCR2+; 28% to 48%, p=0.063) supramaximal verification phase(s). However, response rates remained unchanged when either zero-based thresholds or smallest worthwhile difference response thresholds were used (50% and 90% confidence intervals, all p>0.05). Supramaximal verification phases reduced random variability in VO2peak response to HIIT. Compared with separate-day testing (INCR2 and INCR2+), the incorporation of a same-day verification (INCR1+) reduced CI widths the most. Researchers should consider using a same-day verification phase to reduce uncertainty and better estimate VO2peak response rate to HIIT

Tenofovir disoproxil fumarate induces peripheral neuropathy and alters inflammation and mitochondrial biogenesis in the brains of mice.

Mounting evidence suggests that antiretroviral therapy (ART) drugs may contribute to the prevalence of HIV-associated neurological dysfunction. The HIV envelope glycoprotein (gp120) is neurotoxic and has been linked to alterations in mitochondrial function and increased inflammatory gene expression, which are common neuropathological findings in HIV+ cases on ART with neurological disorders. Tenofovir disproxil fumarate (TDF) has been shown to affect neurogenesis in brains of mice and mitochondria in neurons. In this study, we hypothesized that TDF contributes to neurotoxicity by modulating mitochondrial biogenesis and inflammatory pathways. TDF administered to wild-type (wt) and GFAP-gp120 transgenic (tg) mice caused peripheral neuropathy, as indicated by nerve conduction slowing and thermal hyperalgesia. Conversely TDF protected gp120-tg mice from cognitive dysfunction. In the brains of wt and gp120-tg mice, TDF decreased expression of mitochondrial transcription factor A (TFAM). However, double immunolabelling revealed that TFAM was reduced in neurons and increased in astroglia in the hippocampi of TDF-treated wt and gp120-tg mice. TDF also increased expression of GFAP and decreased expression of IBA1 in the wt and gp120-tg mice. TDF increased tumor necrosis factor (TNF) α in wt mice. However, TDF reduced interleukin (IL) 1β and TNFα mRNA in gp120-tg mouse brains. Primary human astroglia were exposed to increasing doses of TDF for 24 hours and then analyzed for mitochondrial alterations and inflammatory gene expression. In astroglia, TDF caused a dose-dependent increase in oxygen consumption rate, extracellular acidification rate and spare respiratory capacity, changes consistent with increased metabolism. TDF also reduced IL-1β-mediated increases in IL-1β and TNFα mRNA. These data demonstrate that TDF causes peripheral neuropathy in mice and alterations in inflammatory signaling and mitochondrial activity in the brain

A Reactor Core Modification to Enhance Beams for Thermal Neutron Spectrometers

Prepared for Presentation at the 1965 Annual Meeting of the American Nuclear Society, June 21 - 24 at Gatlinburg, Tennesseehttp://deepblue.lib.umich.edu/bitstream/2027.42/86070/1/MMPP Bullock-Daniels-King 1965.PDF2

P1NP and β-CTX-1 responses to a prolonged, continuous running bout in young healthy adult males: a systematic review with individual participant data meta-analysis.

Circulating biomarkers of bone formation and resorption are widely used in exercise metabolism research, but their responses to exercise are not clear. To quantify group responses and inter-individual variability of P1NP and β-CTX-1 after prolonged, continuous running (60-120 min at 65-75% VO2max) in young healthy adult males using individual participant data (IPD) meta-analysis. The protocol was designed following PRISMA-IPD guidelines. Changes in P1NP and β-CTX-1 relative to baseline were measured during, immediately after, and in the hours and days following exercise. Typical hourly and daily variations were estimated from P1NP and β-CTX-1 changes relative to baseline in non-exercise (control) conditions. Group responses and inter-individual variability were quantified with estimates of the mean and standard deviation of the difference, and the proportion of participants exhibiting an increased response. Models were conducted within a Bayesian framework with random intercepts to account for systematic variation across studies. P1NP levels increased during and immediately after running, where the proportion of response was close to 100% (75% CrI: 99 to 100%). P1NP levels returned to baseline levels within 1 hour and over the next 4 days, showing comparable mean and standard deviation of the difference with typical hourly (0.1 ± 7.6 ng·ml-1) and daily (-0.4 ± 5.7 ng·ml-1) variation values. β-CTX-1 levels decreased during and up to 4 hours after running with distributions comparable to typical hourly variation (-0.13 ± 0.11 ng·ml-1). There was no evidence of changes in β-CTX-1 levels during the 4 days after the running bout, where distributions were also similar between the running data and typical daily variation and (-0.03 ± 0.10 ng·ml-1). Transient increases in P1NP were likely biological artefacts (e.g., connective tissue leakage) and not reflective of bone formation. Comparable small decreases in β-CTX-1 identified in both control and running data, suggested that these changes were due to the markers' circadian rhythm and not the running intervention. Hence, prolonged continuous treadmill running did not elicit bone responses, as determined by P1NP and β-CTX-1, in this population. The protocol for this review was pre-registered on the Open Science Framework prior to implementation (https://osf.io/y69nd)

Influence of adipose tissue mass on bone mass in an overweight or obese population: systematic review and meta-analysis

Context: The scientific literature shows conflicting evidence about the relationship between adiposity and bone mass in overweight and obese populations. Objective: The aim of this review was to quantify the correlation between adipose mass (absolute and relative) and bone mineral density (BMD) in overweight and obese populations. Data Sources: Three databases were searched electronically. In addition, reference lists of relevant articles were screened. Study Selection: A total of 16 studies, comprising 2587 participants and 75 correlation coefficients were selected for inclusion in the review. Data Extraction: Data were extracted from each study using a standardized form. Results: Multilevel modeling indicated opposing relationships between BMD and adiposity: absolute adiposity correlated positively, and relative adiposity negatively, with BMD. Sex and age were the primary moderators of these relationships. Strong evidence supported a negative relationship between relative adipose mass and BMD in men (R = -0.37; 95%CI, -0.57 to -0.12) and in those aged less than 25 years (R = -0.28; 95%CI, -0.45 to -0.08). Conclusion: To prevent bone loss in overweight and obese populations, nutrition- and exercise-based interventions that focus on a controlled reduction of adipose mass with concomitant preservation of lean mass are recommended

Tapering practices of New Zealand's elite raw powerlifters

Pritchard, HJ, Tod, DA, Barnes, MJ, Keogh, JW, and McGuigan, MR. Tapering practices of New Zealand's elite raw powerlifters. J Strength Cond Res 30(7): 1796-1804, 2016-The major aim of this study was to determine tapering strategies of elite powerlifters. Eleven New Zealand powerlifters (28.4 ± 7.0 years, best Wilks score of 431.9 ± 43.9 points) classified as elite were interviewed, using semistructured interviews, about their tapering strategies. Interviews were transcribed verbatim and content analyzed. Total training volume peaked 5.2 ± 1.7 weeks from competition while average training intensity (of 1 repetition maximum) peaked 1.9 ± 0.8 weeks from competition. During tapering, volume was reduced by 58.9 ± 8.4% while intensity was maintained (or slightly reduced) and the final weight training session was performed 3.7 ± 1.6 days out from competition. Participants generally stated that tapering was performed to achieve full recovery; that accessory work was removed around 2 weeks out from competition; and deadlifting takes longer to recover from than other lifts. Typically participants stated that trial and error, and changes based on "feel" were the sources of tapering strategies; equipment used and movements performed during tapering are the same as in competition; nutrition was manipulated during the taper (for weight cutting or performance aims); and poor tapering occurred when too long (1 week or more) was taken off training. These results suggest that athletes may benefit from continuing to strength train before important events with reduced volume and maintained intensity. Only exercises that directly assist sports performance should remain in the strength program during tapering, to assist with reductions in fatigue while maintaining/improving strength expression and performance

Feminae: an international multi-site innovative project for female athletes.

Sufficient high-quality studies in sport science using women as participants are lacking, meaning that our knowledge and understanding of female athletes in relation to their ovarian hormone profiles is limited. Consortia can be used to pool talent, expertise, and data, thus accelerating our learning on a given topic and reducing research waste through collaboration. To this end, we have assembled an international multi-site team, described herein, to investigate the effects of the menstrual cycle and oral contraceptive pill phase on aspects of exercise physiology and sports performance in female athletes. We intend to produce an adequately powered, high-quality dataset which can be used to inform the practices of female athletes. Our approach will also employ research transparency – through the inclusion of a process evaluation - and reproducibility – through a standardised study protocol